By Michael Stahl In the penultimate episode of season three of Casual — the Hulu dramedy about a nearing-40 divorcée and mom, Valerie, who’s tossed into 2010s dating culture — viewers are whisked away to a more innocent time. It’s 1999: September 11th hasn’t happened yet, nor Hurricane Katrina, the Great Recession or the Capitol Building Insurrection. The only mass shooting most can remember is Columbine, and Star Wars has been contained to a single, mesmerizing trilogy of ground-breaking films with no roman numerals in their official titles. But as far as many viewers in Casual’s target demog…